Search results for "Optical Imaging"
showing 10 items of 75 documents
Investigating different skin and gastrointestinal tract (GIT) pathologies ex vivo by autofluorescence spectroscopy and optical imaging
2017
The skin neoplasias are on a second place in the world statistics of cancer incidence, and gastrointestinal tract (GIT) tumours are also in the “top ten” list. For the most of cutaneous and gastrointestinal tumours could be obtained better prognoses for patients, if an earlier and precise diagnostics procedure is applied. One of the most promising approaches for development of improved diagnostic techniques, is based on optical detection, and analysis of the signatures of biological tissues for detecting the presence of pathological alterations in the investigated objects. It is important to develop and combine novel diagnostic techniques for an accurate early stage diagnosis to improve the…
Place de l’imagerie dans l’évaluation de l’efficacité des traitements dans le cancer du sein
2010
Resume Cette revue decrit le role de differentes methodes d’imagerie pour evaluer la reponse au traitement dans le cancer du sein. Deux situations sont envisageables : celle de la chimiotherapie neoadjuvante du cancer du sein et celle des metastases. Beaucoup de donnees cliniques sont disponibles pour trois criteres : le volume de la tumeur, la captation du fluorodeoxyglucose mesuree en TEP et la perfusion de la tumeur evaluee soit par IRM dynamique, soit en TEP. La TEP au 2-18F fluoro-2-desoxy-D-glucose (FDG) permet la prediction de la reponse apres une ou deux cures de chimiotherapie. De nouvelles approches pourraient prochainement affiner le role de l’imagerie. Ainsi, la TEP a la thymidi…
Acetic acid compared with i-scan imaging for detecting Barrett's esophagus: a randomized, comparative trial.
2013
Background Traditional surveillance in patients with Barrett's esophagus (BE) has relied on random biopsies. Targeted biopsies that use advanced imaging modalities may significantly improve detection of specialized columnar epithelium (SCE). Objective We compared the efficacy of targeted biopsies that used i -scan or acetic acid to random biopsies in the detection of SCE. Design Patients with visible columnar lined epithelium or known BE were randomized at a 1:1 ratio to undergo acetic acid application or i -scan with targeted biopsies. Setting Targeted biopsies were performed based on surface architecture according to the Guelrud classification followed by 4-quadrant biopsies. Patients A t…
Synthesis and study of new fluorescent probes for optical imaging, Cherenkov imaging and multimodal imaging
2015
The goal of this work was to prepare and study new fluorescent probes, which could give rise to novel optical or Cherenkov imaging agents. The first section of this work describes the synthesis of fluorescent subphthalocyanines and phthalocyanines probes, which possess relevant chemicals groups suitable for optical imaging applications. The optical and physico-chemical properties of the new probes were carefully examined to ensure they comply with the specification of the fluorophores for the desired application. The second part focused on the subsequent development of a few selected probes into real imaging agents. The biovectorisation of subphtalocyanines was achieved upon conjugation of …
Integration of Indocyanine Green Analogs as Near‐Infrared Fluorescent Carrier for Precise Imaging‐Guided Gene Delivery
2020
Codelivery of diagnostic probes and therapeutic molecules often suffers from intrinsic complexity and premature leakage from or degradation of the nanocarrier. Inspired by the "Y" shape of indocyanine green (ICG), the dye is integrated in an amphiphilic lipopeptide (RNF). The hydrophilic segment is composed of arginine-rich dendritic peptides, while cyanine dyes are modified with two long carbon chains and employed as the hydrophobic moiety. They are linked through a disulfide linkage to improve the responsivity in the tumor microenvironment. After formulation with other lipopeptides at an optimized ratio, the theranostic system (RNS-2) forms lipid-based nanoparticles with slight positive z…
A nitroreductase and glutathione responsive nanoplatform for integration of gene delivery and near-infrared fluorescence imaging
2020
A novel platform rationally integrating indocyanine green analogues and an arginine-rich dendritic peptide with both nitroreductase (NTR) and glutathione (GSH) reduction responsive linkers was developed. This multifunctional platform can enable selective and efficient gene delivery and specific turn-on fluorescence imaging in tumors.
Mapping of the perigastric lymphatic network using indocyanine green fluorescence imaging and tissue marking dye in clinically advanced gastric cance…
2022
Abstract Background Using indocyanine green (ICG) fluorescence imaging and tissue marking dyes (TMDs), perigastric lymphatic mapping and their pathological correlation were examined to see whether ICG staining covers all metastatic lymph nodes (LNs) in advanced gastric cancer (AGC). Methods Patients with AGC who underwent open distal or total gastrectomy were enrolled. ICG was serially injected intraoperatively into the subserosa along the greater and lesser curvatures. Stomach specimens were examined under a near-infrared camera. ICG-stained LNs were named, excised, and tattooed with different colored TMDs to retrace the exact location after pathological examinations. Results A total of 68…
Fundamentals of automated human gesture recognition using 3D integral imaging: a tutorial
2020
Automated human gesture recognition is receiving significant research interest, with applications ranging from novel acquisition techniques to algorithms, data processing, and classification methodologies. This tutorial presents an overview of the fundamental components and basics of the current 3D optical image acquisition technologies for gesture recognition, including the most promising algorithms. Experimental results illustrate some examples of 3D integral imaging, which are compared to conventional 2D optical imaging. Examples of classifying human gestures under normal and degraded conditions, such as low illumination and the presence of partial occlusions, are provided. This tutorial…
Hyperspectral venous image quality assessment for optimum illumination range selection based on skin tone characteristics
2014
Background Subcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc. Methods To enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obt…
Dual Cherenkov Radiation-Induced Near-Infrared Luminescence Imaging and Photodynamic Therapy toward Tumor Resection
2020
International audience; Cherenkov radiation (CR), the blue light seen in nuclear reactors, is emitted by some radiopharmaceuticals. This study showed that (1) a portion of CR could be transferred in the region of the optical spectrum, where biological tissues are most transparent: as a result, upon radiance amplification in the near-infrared window, the detection of light could occur twice deeper in tissues than during classical Cherenkov luminescence imaging and (2) Cherenkov-photodynamic therapy (CR-PDT) on cells could be achieved under conditions mimicking unlimited depth using the CR-embarked light source, which is unlike standard PDT, where light penetration depth is limited in biologi…